diff --git a/paddle/fluid/memory/allocation/retry_allocator_test.cc b/paddle/fluid/memory/allocation/retry_allocator_test.cc
index 8b24ff28b76301496d8cfd66774306b4a74cee88..670dc9ffba2e8fae4b84246eb35bd3f047b02693 100644
--- a/paddle/fluid/memory/allocation/retry_allocator_test.cc
+++ b/paddle/fluid/memory/allocation/retry_allocator_test.cc
@@ -43,7 +43,7 @@ TEST(RetryAllocator, RetryAllocator) {
   std::unique_ptr<LockedAllocator> locked_allocator(
       new LockedAllocator(std::move(best_fit_allocator)));
 
-  size_t thread_num = 8;
+  size_t thread_num = 4;
   size_t sleep_time = 40;
   size_t extra_time = 10;